Question

помогите дам 20 баллов
это алгебра​

Answer 1

Ответ:

а)

$\frac{4}{a} + \frac{a - 4}{a + 3} = \frac{4(a + 3) + a(a - 4)}{a(a + 3)} = \frac{4a +12 + {a}^{2} - 4a}{a(a + 3)} = \frac{12 - {a}^{2} }{a(a - 3)} = \frac{12 - {a}^{2} }{ {a}^{2} - 3a}$

б)

$\frac{2 {x}^{2} }{ {x}^{2} - 4 } - \frac{2x}{x + 2} = \frac{2 {x}^{2} }{ (x - 2)(x + 2)} - \frac{2x}{x + 2} = \frac{2 {x}^{2} - 2x(x - 2) }{(x - 2)(x + 2)} = \frac{2 {x}^{2} - 2 {x}^{2} + 4x }{(x - 2)(x + 2)} = \frac{4x}{ {x}^{2} - 4 }$